Technical Field
The invention relates to a method for lightning warning with a large number of wind energy installations, in particular with a part of a wind farm, and a wind energy installation and a wind farm, as well as a network of wind energy installations and/or wind farm installations for lightning warning, and a use of a system for weather prediction, in particular for thunderstorm and/or lightning warning.
Description of the Related Art
Wind energy and wind power are responsible for an ever-growing proportion of global electricity generation, and are therefore becoming of significant value. With the rising number of wind energy installations and wind farm installations, however, the amount of servicing work and the time required for servicing the wind energy installations and wind farms are also increasing at the same time. A large amount of servicing work is, however, associated with high costs and a high level of logistical planning for the servicing work and the servicing personnel. An important point to be taken into account when planning the servicing work is to avoid unnecessary down-times during which servicing work is interrupted by stormy conditions, in particular during thunderstorms with lightning strikes on wind energy installations. The probability of a lightning strike is particularly high in the case of wind energy installations, since, due to their construction, they often constitute the highest point in the surroundings, and are thereby a preferred point for atmospheric discharges.
Public weather predictions are typically used for lightning and/or thunderstorm warning; locally, and in particular in relation to a particular location of a wind energy installation, these are very imprecise and may not enable lightning prediction at all.
The prediction of a lightning strike in a wind energy installation, in particular during the course of servicing work, must however be very reliable, since in the event of an actual lightning strike there is a high risk to safety, and even a risk to the life of the servicing personnel. On the other hand, servicing work should however only be interrupted when there genuinely is a sufficient probability of a lightning strike, so that servicing work is not interrupted unnecessarily.
It would therefore be desirable to provide a method and apparatus with which it is possible to predict a lightning strike at an early stage or to detect it, in particular a lightning strike in a particular wind energy installation, and to issue a corresponding warning announcement so that the servicing personnel can interrupt the servicing work and/or the wind energy installation can be switched off. When the risk of the lightning strike has then receded, the servicing work can be resumed and/or the wind energy installation can be switched back on. In particular it would be desirable for the potential place and time of a lightning strike to be predicted in a precise and reliable manner.
For the prediction of the weather, and in particular for the prediction of thunderstorms, the derivation or prediction of a state of the atmosphere for the future from a past and a present weather condition of the atmosphere, using known physical rules, is known. What are known as non-linear equations are used here, in which even small changes in the initial conditions lead to a large variation in the results, in this case the weather forecast. This phenomenon is also known as the butterfly effect.
The initial conditions or data, in particular the measured data or measured values for the environment and/or atmospheric conditions that provide information about the present state of the atmosphere, are registered using a network of ground measuring stations. The measuring stations here typically register the wind speed, temperature, air pressure and humidity, as well as the quantity of precipitation. A reliable weather prediction is only possible when a sufficiently large number of measuring stations that collect weather data are present.
The measuring stations known from the prior art are, however, often arranged close to the ground, so that the measured (weather) data measured, in particular the environmental parameters, are falsified by ground effects, for example by heat or cold stored in the ground. Incorrect measured data however does not permit a reliable prediction of the weather for a specific place. In addition, data relating to electric or electromagnetic fields is also not collected by the known ground measuring stations, so that a lightning prediction is practically impossible.
The German Patent and Trade Mark Office has researched the following documents on this topic: DE 10 2012 222 973 A1, AT 389 012 B and brieselang.net (an internet site relating to preventive lightning protection).